This is several equity curves of a player

If you think that this guy has some special ability,
it's an illusion since the MULTIPLE equity curves are drawn from a fair coin toss. This illusion has been discovered only in 20th century from mathematician Levy and called commonly "persistency of chance", more metaphorically "Fundamental Injustice Law of Nature" " and more technically arc sinus law. This law is NOT AT ALL INTUITIVE as one would expect that the number of curves below and above zero somehow counterbalance each other.

Yeah, I get it. You could make a neural network or some other kind of system that would capture every single favorable coin toss in hindsight, but it would have no real predictive power. You could still get lucky, though. So how much out of sample testing or real trading experience should you expect to need to demonstrate that the neural network was bogus?

You can in fact identify patterns from say a sequences of 10000 trials that each producing some sort of bias for the next flip.

Such patterns may/may not work at all on another sequence of 10000 trials.

Translate that to the market, a system or method that supposed to perform must be fundamentally sound in terms of the design and rules must be sensible. Otherwise, you are just twisting around the paremeters to fulfill your fantasy of owning a model that perform best over your historical data

One good measure is how stable the system / method performs over time.

If you think that this guy has some special ability,
it's an illusion since the MULTIPLE equity curves are drawn from a fair coin toss. This illusion has been discovered only in 20th century from mathematician Levy and called commonly "persistency of chance", more metaphorically "Fundamental Injustice Law of Nature" " and more technically arc sinus law. This law is NOT AT ALL INTUITIVE as one would expect that the number of curves below and above zero somehow counterbalance each other.

For a proper analogy to trading you need the coin flip to incur transactions costs. I think you'll find that if you do that, the chance of getting a set of distributions like those shown above is rather low.

In any case, those distributions don't look particularly impressive. I certainly wouldn't back a trader showing me a curve that mediocre.